I find that most Republicans do not understand anything more than textbook basic economics. ITs much more complicated and less cut and dry than the "basics of economics".
Oil prices for example do not follow the very simple rule of supply and demand. The prices are set by what the people will or can afford to pay, the fulcuation is not based on increasing or decreasing supply (although the oil companies try to claim that). A tax on gas does not result in a 1 for 1 price increase for example. An oil tanker spilling its load should not result in a price increase of gas because it barely affects the huge supply. When the profits of a company are so HUGE, its clear that the price of the product is not set based on supply and demand but set by how much they can get away with charging for the product, because they would still operate at a smaller profit margin if they were forced to do so.